In this work, a novel bimetallic ternary composite (AuCu-P25-rGO) had been designed and prepared, and been used as a high-performance photocatalyst. The morphology, chemical composition, physical structure and photoelectric property were confirmed by XRD, TEM, BET analysis, FT-IR, Raman, XPS, UV-vis DRS, Photoluminscence spectra and transient photocurrent responses techniques. The photocatalysts possessed higher catalytic activity than P25, P25-rGO, AuCu-P25, Cu-P25-rGO, Au-P25-rGO for photodegradation of organic pollutant (2-nitrophenol) under UV-vis light. Importantly, the molar ratio of Au:Cu exhibited significant influence on the photocatalytic property, and AuCu-P25-rGO with Au/Cu molar ratio = 1:1 showed higher activity than these with Au/Cu molar ratio = 1:3 and 3:1. In addition, Au1Cu1-P25-rGO could excellently photodegradation of organic dyes (Rhodamine B and methylene blue). The enhanced photocatalytic performance of AuCu-P25-rGO composites can be attributed to three reasons as follows: (1) surface plasmon resonance (SPR) effect of AuCu bimetallic nanoparticles; (2) outstanding conductivity and adsorptivity of rGO; (3) the poly morphs junction formed by mixture of anatase and rutile of P25.